


il faut casser le noyau pour avoir l’amande

by SympatriCuckoo



Category: Undertale (Video Game)
Genre: Body Worship, Bondage, Cunnilingus, Ecto-Vagina, Face-Sitting, Incest, M/M, Penetrative Sex, ecodick, ectotongue, tags probably make it seem kinkier than it really is
Language: English
Status: Completed
Published: 2016-03-20
Updated: 2016-04-15
Packaged: 2018-05-28 00:25:36
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,319
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6306424
Author URL: https://archiveofourown.org/users/SympatriCuckoo/pseuds/SympatriCuckoo
Summary: <blockquote class="userstuff">
              <p>
  <em>“NOT A WORD” Papyrus had reminded before beginning, “OR WE STOP.”</em>
  <br/>
  <br/>
  <em>Fastening the gag in place himself, Sans paused and nodded. Understanding passed between them without words. </em>
</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> When I started writing this, it was supposed to be Sans/Pap, not Pap/Sans. But Sans wouldn't stop making puns, so this was born. 
> 
> I'm not entirely satisfied with the way this turned out, but I think this is probably the best it's going to get right now. The ending really bugs me, too; maybe I'll write penetrative sex in another chapter.
> 
> Dedicated to GoodTimesNewRoman for their motivation to continue this fic that had FIVE rewrites.

Papyrus beams, pleased. He can feel his magic coil low in his pelvis, aching to be released. But he pushes it down, intent on pleasuring Sans first and foremost.

 

Sans is sprawled, gagged and half-naked on the floor, legs spread and arms bound behind his back with Papyrus' magic. His cock is achingly hard, dribbling blue magic to pool on the floor between his legs.

 

Papyrus crouches down. One hand moves up under Sans' shirt, rubbing up and down the sternum before diving inside his rib cage and caressing the more sensitive undersides. His other hand moves down the lumbar vertebrae to the sacrum where he toys with the holes, sticking his fingers into the sacral foraminae and dipping down to fondle his coccyx.

 

Sans responds readily, arching into Papyrus' hands and writhing as best he can in his bonds. His body language practically screams, 'fuck me'. But that's for later, much later. Right now, Papyrus wants to explore, tease, worship his brother's body; he wants to bring that normally composed mien crashing down.

 

Except for heavy breathing and muffled noises, it's quiet in the room, the silence amplifying the sounds of Sans being loved. It was slow moving when they'd first started. When they were moving beyond being only siblings, Sans' sardonic quips and irreverent comments interfered with the change, defenses against further intimacy, against vulnerability.

 

“ _NOT A WORD” Papyrus had reminded before beginning, “OR WE STOP.”_

 

_Fastening the gag in place himself, Sans paused and nodded. Understanding passed between them without words._

 

Gagged, Sans can't provoke Papyrus into leaving in a huff, and while Papyrus would dearly love to able to hear Sans without the gag, this is what his brother wants.

 

Leaning forward, hands still occupied, Papyrus nuzzles his face gently against Sans'-a skeleton kiss. Eyes hazy, Sans leans into the touch, then gasps as Papyrus nuzzles against his mouth, against the gag, only to pull away slightly and lick the hard plastic.

 

Papyrus loves Sans' body: the shape of his rib cage, somewhat shorter and stouter than his own; the texture under his hand as he moves from bone to cartilage, the little bumps on his sternum; and the smaller and more sensitive xyphoid process, a mere touch against which causes Sans to gasp and twitch.

 

Thoroughly and methodically, Papyrus kisses and explores every rib, inside and outside, with hand and tongue. He wants to take and lavish every inch of his body with his love and affection and magic. He wants to leave no area untouched and unexplored so that whenever Sans is alone, he'll remember, so his entire body is one memento.

 

But most of all, he wants Sans to know, bone and soul, that he's loved, cherished, _ adored  _.

 

By the time Papyrus finishes his exhaustive appreciation of Sans' chest and thoracic spine, Sans is quivering in bliss and arousal, love, wonder and desire clear on his face as he stares down at Papyrus.

 

Papyrus can feel himself warm to his soul, content and fulfilled with the knowledge that he can make his brother feel so good, so relaxed and open in his responses; feels proud and humbled as Sans lays himself bare. This is the culmination of their relationship, a physical testament to their mutual love, respect and trust.

 

Pressing one last kiss against Sans' sternum, Papyrus sits back and shares an equally loving and happy look with Sans, hands moving down to caress Sans' femurs. Sans shudders and arches, whining into the gag as Papyrus' hand moves steadily higher, reaching his pelvis and fondling the iliac crest and pubic bone but avoiding his dick, much to Sans' chagrin.

 

Sans huffs, wriggling to try to get Papyrus to touch his cock, even if only by accident. But in this, Papyrus is not merciful.

 

He moves his hands so that they are resting on the outside of Sans' hips, fingers idly tracing around the joint where femur and pelvis meet, and bends over, pressing a kiss against the inside of Sans' femurs before nibbling the spot lightly, worrying the area with his teeth and then soothing it with his tongue.

  
At the touch of teeth against bone, Sans jolts slightly before groaning and arching into the sensation. It's a sensual pattern, one that Papyrus repeats up and down femurs and shins, drawing little broken cries from Sans.

 

These cries crescendo into a sharp yelp as Papyrus drags his fingers over the arches of Sans' feet. Mischievously, Papyrus crooks his fingers and begins tickling in earnest. Sans twists around, gag muting his laughter to loud groaning, spreading his legs more to try to evade the tickling.

 

Papyrus shuffles further forward until he's kneeling between Sans' legs, then reaches out to grab both of Sans' feet. Like the rest of his brother, they're on the smaller side-narrow enough that Papyrus can hold them in one hand by the toes.

 

Slowly, touch just shy of tickling, Papyrus trails his knuckles down each metatarsal, each phalanges. After the tickle assault, this proves too much for Sans' over-sensitized nerves; toes spreading and curling, back arching, Sans throws his head back with a long stuttering moan.

 

For a second Papyrus pauses, trying to hold onto his restraint. Sans' reactions are arousing sure, but that moan, both breathy and guttural: it was enough to tempt even the most determined of monsters.

 

Resolute, he briskly presses a kiss to each foot before leaning forward onto his forearms and throwing Sans' legs over his shoulders, scooting closer until he's face-to-face with Sans' cock.

 

From where he's kneeling, Papyrus can look up and see Sans' dick and face framed between spread open legs. Sans' dick is flushed a pretty blue, darker than the saliva dripping down his chin, darker even than the blue blush on his face.

 

Making and maintaining eye-contact, Papyrus bends down and licks up a drop of pre-cum dripping down from the head, running along the side. From above, he can hear Sans let out a gasp, clearly biting back words.

 

Papyrus allows his magic to issue forth, conjuring his own cock. Theatrically, Papyrus opens his mouth and wraps his dextrous tongue around the base of Sans' cock. He leisurely drags his curled tongue up and down the length, gratified to see Sans' pupil flutter quickly between blue and white.

 

On the second down-stroke, when his tongue is again curled at the root, Papyrus gently rubs the tip of a canine against the slit. A soft wheeze comes from above and Papyrus quickly soothes the head with his tongue before taking as much into his mouth as he can.

 

He's teased them both enough. Shifting so that his one hand is gripping the base of Sans' cock, his other palming and stroking himself, Papyrus sets a blistering pace, sucking enthusiastically and jacking what he can't manage without gagging. His eyes are focused on Sans as his brother come apart above him.

 

Sans' reactions are heady, fueling his own lust: the way the color in Sans' cheeks rises to a hectic flush; the adorable way that his head keeps lolling backward in bliss only to jerk forward again in order to keep watching Papyrus; the sounds, soft and guttural and so hot, were a language of their own, directing Papyrus in his efforts; the way the magic of their conjured appendages begin to react, sending emotions and sensations through each others' soul. Papyrus can feel Sans' pleasure of course, but also love, wonder, and, small but still present, a vague sense of anxiety.   
  
Well, that just wouldn't do.

 

Papyrus had sworn to make Sans feel wonderfully, stupendously amazing and nothing, especially his brother's tendency to ruminate and over-think things, would stand in the way of that goal. Without hesitation, Papyrus focuses on how he feels, trying to send as much love and affection and happiness as possible to blanket and dispel the worry Sans is still feeling.

 

Helpless under the combined assault of physical and emotional pleasure, Sans tenses further, breath shuddering out of him as he comes, hips jerking up and stilling, pressed against Papyrus' face. Papyrus swallows around him, milking him through the orgasm and drinking down his released magic. He continues suckling softly, only stopping when Sans makes a discontented noise and tries to shuffle away.

 

Gently, Papyrus shifts Sans' legs off his shoulders, dispels his bindings, then removes the gag from his mouth. Sans lies there, eyes closed and breathing deeply, mouth still open as though he has forgotten he can close it.

 

He looks well-spent. He looks _debauched_.

 

Slowly, as though every limb was lined with lead, Sans sits up from his slouch and reaches out for Papyrus, wrapping his hand around Papyrus' own grip on his cock. Hand in hand, they pump over the length, Papyrus' breathing becoming progressively more labored.

 

With one last flick of the wrist, thumb swirling over the head, Papyrus comes with a shout, magic splattering over their hands and onto the floor.

 

Papyrus all but collapses next to Sans, cuddling into Sans' side, heedless of the mess they've made in his post-coital daze. Sans envelops him a hug, and together they lie in contented silence.

 

* * *

 

 

Bonus: 'He can think of a few puns that are _hard to swallow_ ' or How the first version got derailed:'

 

[Papyrus is bound and gagged on the floor, a vibrator buzzing away inside of him]

 

Sans pushes his shorts down and takes himself in hand. Catching Papyrus’ eyes, he jerks himself twice before rubbing the tip around Papyrus’ stretched mouth, mixing saliva and pre-cum together, painting his brother’s jaw green.

 

Papyrus looks pleadingly up at Sans.

 

“You want something, bro?”

 

“AHFAH FANT HFOU.”

 

“Gotta speak up.”

 

“AH FWAU AHFAH FANT HFOU!” With each sound, saliva seeps from around the gag.

 

“Sorry, didn’t quite catch that.”

 

Papyrus huffs and glares. With a grunt of effort, he raises himself to his feet, knees pressing uncomfortably against his chest. It’s awkward and he’s having trouble balancing and he half-falls face-first into Sans’ upper thighs. The vibrator falls out of him with a clatter.

 

Surprised, Sans reaches down to steady his brother, a hand on either shoulder. “What’s the matter, Pap? Can’t _stand_ it anymore?”

 

Papyrus stares up at him, brows furrowed in disapproval.

 

“I’m _afrayed_ that you look to be in a bit of a _knotty_ situation.”

 

If glares could kill…

 

“Sorry, sorry.” Sans chuckles, unbuckling the gag.

 

“SANS! WHAT IS THE MATTER WITH YOU, YOU BONEHEAD?!” Sans stifles a giggle. “THIS IS PORN TIME! TRY TO BE MORE SERIOUS!” Papyrus somehow manages to convey pouting while not having lips. “NOW LOOK! THE MOOD IS COMPLETELY RUINED!”

 

“Little Pap doesn’t seem to be having any trouble,” Sans points out, pointing to Papyrus’ dick.

 

“HE DOESN’T KNOW ANY BETTER.” A pause and then, “AND NOW YOU’VE GOT ME ADDRESSING MY OWN CONJURED PARTS IN THE THIRD PERSON!”

 

Sans starts shaking with repressed laughter and the blue magic binding Papyrus winks out.

 

 

 


	2. Chapter 2

**Notes for the Chapter:**

> Warnings: ecto-parts (vag, dick, tongue); face-sitting; a skeleton eating out another skeleton; incest; actual fucking penetration; 1 use of the word cunt; there might be more, but none that jump out at me
> 
> This…I was having trouble ending this. I’m not entirely happy with the pacing at the end, but that’s the best I can come up with. Maybe later I’ll find the inspiration and ability to fix it. But right now, that’s not possible.
> 
> And, yet again, I was having trouble writing penetration. But what else is new.
> 
> I hope you will enjoy.

They lie together in Papyrus' bed, naked and cuddling. It's warm and comfortable and whenever one of them shifts, bone rubs against bone. It's sensual, and, oftentimes, they move slightly-lifting an arm, moving a leg, pulling the other closer-just to feel the sensation of the others body entwined around their own.

 

When Papyrus rolls them over, straddling Sans, it's a natural extension, a continuation of their intimacy, rather similar to the next act in a play.

 

Sans reaches up, twining his arms around Papyrus' shoulders and pulls him down for a kiss. Their ribs slot together as Papyrus lays flush against Sans, cradling his head in his hands.

 

They lay like that for a while, trading kisses and caresses.

 

Sans runs his hands over Papyrus' shoulder blades, across the backs of his ribs, following the curve of his spine. He chuckles as Papyrus yelps when he lightly scratches against the cartilage between vertebrae.

 

“Come up here, Paps,” Sans says, gesturing towards the top of the bed. “I wanna thank you for before.”

 

“THANKS ISN'T NECESSARY!” Papyrus responds, sitting up. “I WANTED TO DO THAT AND I ENJOYED IT.”

 

“Then this is something that I want to do for you. C'mon. Knees on the pillows, hands on the car tail wing.”

 

Papyrus gets off of Sans and crawls up the bed. “IS THIS GOING TO BE MESSY?” Papyrus asks, suspicious. “BECAUSE I DON'T WANT TO HAVE TO DO _ANOTHER_ LAUNDRY.”

 

Sans half-turns, admiring the view. “Don't worry, I'll clean it _all up._ ”

 

“OH. ALRIGHT, THEN! LIKE THIS?” Papyrus cranes his head around. He's kneeling on the pillows, legs spread shoulder-width apart and hands braced against the back of the car.

 

“ _Juuust_ like that...” Sans says, idly rubbing his pubis before scooting underneath Papyrus' spread legs. From where he's lying he has the perfect view of the inside of Papyrus' pelvis. He licks his teeth as he contemplates where to start, then reaches up to gently tweak his tailbone.

 

Papyrus gasps and Sans rubs the edges of the coccyx between thumb and forefinger. Papyrus presses down into the sensation. He's close enough now that Sans conjures his tongue, magic casting a blue glow. It lights up the bone and casts dips and creases into stark shadow, just begging to be explored.

 

With care, he licks along the ridges of the fused vertebra, spiraling higher. When he reaches the sacrum, he lunges up and pulls Papyrus down onto his face, sucking his tailbone into his mouth.

 

Papyrus cries out, spine arching as the sensitive bones are suddenly encased in magic and suckled with mouth and tongue. Sans has to reach out to steady him, one hand on the back of the sacrum, kneading and exploring, looking for the sensitive foraminae.

 

When he finds them, he exploits the erogenous zone ruthlessly, circling and fingering them. In the wider foraminae, Sans is able to fit the tips of two fingers into them, one from the back and one from the front, so that they meet in the middle; and when he wiggles his fingers, Papyrus howls, shifting restlessly over Sans' face.

 

He torments Papyrus until wetness seeps onto his forehead. With one last slurp, he eases back and withdraws his fingers, earning an unhappy whine.

 

Papyrus' entire pelvis is alight with orange. In the middle of the empty space in his pelvis hangs the folds of his pussy, puffy and shining. At the top, like a jewel in a crown, is his clit, slightly engorged.

 

Sans reaches up and pulls Papyrus down, arms and hands hugging Papyrus' upper thighs, until he's crouched lower, pelvis sticking out. Slowly and gently, Sans rubs circles over the hood with his tongue and Papyrus bucks wildly, pushing his crotch further into Sans' face with a cry.

 

Sans continues lapping at the hood, careful not to put too much pressure against the clit itself; he slides his hand down to wet, orange folds, fondling them, slicking his fingers with Papyrus' juices. Then he switches, hands moving up to rub against the hood to where it connects to bone, mouth and tongue moving down to lick and suck at the labia.

 

Papyrus is drenched, lubrication and spit mixing, smearing onto Sans' face with every buck of Papyrus' hips. He teases the outside of the hole, dipping in with the tip of his tongue, every time staying longer and longer until he's thrusting in to the first inch, wiggling his tongue around.

 

Sans is aroused; he loves the taste, loves the feel of Papyrus riding his face, body out of control and overloaded with pleasure. Sans points his tongue, folding the sides over, and begins thrusting in and out, drinking down Papyrus' fluids.

 

Obscene, wet slurping sounds ring out, mingling with Papyrus' needy cries which grow steadily, becoming more and more frequent. Sans' wrist is beginning to hurt, but he continues rubbing, the way eased occasionally with saliva and natural lubrication as he cycles between clit and cunt with his tongue.

 

Suddenly, Sans feels hands on the back of his head, pushing his face further into Papyrus' pussy,humping onto Sans' tongue. He looks up: Papyrus' head is thrown back, spine arching as he pants, trying to get air only to use it up crying in pleasure, pleading for more. He continues fucking into Papyrus with his tongue until his hole spasms around him, magic drenching his tongue. Sans swallows it down, then hunts for any remaining juices, sucking on the folds again before laving over the clit and hood.

 

Licking and stroking, Sans continues relishing affection on his brother's body, slowly starting to build up Papyrus' arousal again. When Papyrus starts rocking and forth, Sans knows he's ready.

 

Papyrus shrieks with surprise as he's pushed over so his head is at the foot of the bed, Sans cradled between his legs.

 

“You alright there, Paps?” Sans asks, an eyebrow raised.

 

“A LITTLE WARNING WOULD'VE BEEN NICE,” Papyrus grouses. Nevertheless, he hugs Sans close, annoyance more superficial, legs spread and bent off to the sides.

 

Sans' eye flickers as his dick materializes. He slides himself up and down the folds, getting his cock wet and teasing both himself and Papyrus, before entering.

 

It's hot and wet and so so tight. They both groan when Sans is balls deep: Papyrus from the stretch and the sensation of being filled; Sans from the feeling of muscles squeezing around him, seemingly molding to the shape of his cock. Sans pauses, collecting his bearings and savoring the feeling.

 

Sans sets a slow pace. The first thrust has Papyrus mewling, arching into it, and Sans grinds into him at the end of each stroke, changing the angle each time. When Papyrus keens, throwing his arms around him and hooking his legs around his waist, Sans knows he's found the best position.

 

Sans fucks into Papyrus, short and fast, the head pressing against the g-spot before pushing past, further inside Papyrus' hole. Each thrust rocks Papyrus forward, until he's against the foot of the bed, head thrown back against the dash, eyes closed in pleasure and mouth open wide.

  
“FASTER.”

 

“HARDER.”

 

“SANS.”

 

“PLEASE.”

 

Papyrus babbles begging for more, and Sans obliges to the best of his ability, holding him steady and slamming into him. Papyrus' hands scrabble over Sans' back, fingers catching on his ribs as he tries to pull Sans further into him, bucking to get him deeper.

 

Burying his face into the base of Papyrus' neck, Sans is panting and sweating with exertion, with trying to hold back his own orgasm. But Papyrus makes such a hot picture, writhing and pleading beneath him. Like this, Sans feels like he's drowning in Papyrus, in his voice, in his smell, in his magic. And it's just too much.

 

“Ngh, Paps,” he grits out. “Not gonna-gonna come.”

 

“HAH, SANS. PLEASE. ALMOST THERE.”

 

“C-can't, Paps. Shit.”

 

Sans comes, thrusting shallowly, Papyrus' walls milking his release. He pulls out and watches as the labia fold back together, a thin line of his come dribbling out.

 

Bending down, Sans goes down on Papyrus again, licking up his own jizz before spreading Papyrus' folds and delving inside with both fingers and tongue, cleaning Papyrus of himself before turning his attentions fully to his brother's pleasure.

 

Sans pulls out all the stops, uses every trick he knows to make Papyrus lose his mind. He tugs lightly at his folds, runs the flat of his teeth against his clit before soothing with mouth and tongue. Sans holds Papyrus down as he bucks against his face, coordination shot as he comes hard, squirting from the unintended edging, soaking the bed.

 

Sans sits back, trying to commit this scene to memory-Papyrus debauched on the bed, pelvis and genitals covered in his own come, body twitching with the after-effects of his orgasm-before he bundles Papyrus up and teleports them both to his room for some more, well-earned, cuddle time.

 

And maybe, just maybe, Papyrus will be relaxed enough that he won't freak out over the bed.

 

 

**Author's Note:**

> Bonus: 'He can think of a few puns that are _hard to swallow_ ' or How the first version got derailed:
> 
> [Papyrus is bound and gagged on the floor, a vibrator buzzing away inside of him]
> 
> Sans pushes his shorts down and takes himself in hand. Catching Papyrus’ eyes, he jerks himself twice before rubbing the tip around Papyrus’ stretched mouth, mixing saliva and pre-cum together, painting his brother’s jaw green.
> 
> Papyrus looks pleadingly up at Sans.
> 
> “You want something, bro?”
> 
> “AHFAH FANT HFOU.”
> 
> “Gotta speak up.”
> 
> “AH FWAU AHFAH FANT HFOU!” With each sound, saliva seeps from around the gag.
> 
> “Sorry, didn’t quite catch that.”
> 
> Papyrus huffs and glares. With a grunt of effort, he raises himself to his feet, knees pressing uncomfortably against his chest. It’s awkward and he’s having trouble balancing and he half-falls face-first into Sans’ upper thighs. The vibrator falls out of him with a clatter.
> 
> Surprised, Sans reaches down to steady his brother, a hand on either shoulder. “What’s the matter, Pap? Can’t _stand_ it anymore?”
> 
> Papyrus stares up at him, brows furrowed in disapproval.
> 
> “I’m _afrayed_ that you look to be in a bit of a _knotty_ situation.”
> 
> If glares could kill…
> 
> “Sorry, sorry.” Sans chuckles, unbuckling the gag.
> 
> “SANS! COULD YOU NOT?!” Sans stifles a giggle. “STOP LAUGHING! THIS IS PORN TIME! TRY TO BE MORE SERIOUS!” Papyrus somehow manages to convey pouting while not having lips. “NOW LOOK! THE MOOD IS COMPLETELY RUINED!”
> 
> “Little Pap doesn’t seem to be having any trouble,” Sans points out, pointing to Papyrus’ dick.
> 
> “HE DOESN’T KNOW ANY BETTER.” A pause and then, “AND NOW YOU’VE GOT ME ADDRESSING MY OWN CONJURED PARTS IN THE THIRD PERSON!”
> 
> Sans starts shaking with repressed laughter and the blue magic binding Papyrus winks out.


End file.
